There is an increasing need for high luminance light sources in applications from projection systems and high speed industrial inspection to optical fibre-coupled illumination in surgical endoscopy. Therein, bright dis-charge lamps are the state of the art being broadly used today. Recent developments are heading for a combination of solid-state light sources, in particular light emitting diodes (LED), and light converting phosphor elements. Therein, the typically blue or ultraviolet solid-state based light is converted to light having less energy and a longer wave length by a transmission through the phosphor element.